The present invention relates to a connector which is comprised of a plug connector and a receptacle connector, each having a plurality of contacts, and which is designed so that the corresponding contacts can be engaged with or disengaged from each other through a single manual snap in or out operation.
A conventional plug connector has such a structure as shown in FIGS. 1 and 2. The plug connector, indicated generally by 11, has a plurality of contacts incorporated in a body 12 of an insulating material. The contacts project at one end from the front end face of the body 12 to form plug contact pins 13 and are led out at the other end from the rear end face of the body 12 to form terminals 14. A shell 15 made of metal is mounted on the front end face of the body 12 in a manner to surround an array of all the plug contact pins 13. The shell 15 has formed integrally therewith a flange 15a which protrudes from the peripheral surface of the body 12.
Conventionally the plug connector 11 is received or housed in a cover 16 with the flange 15a secured by means of screws 20 to the front wall of the cover 16. Resilient metallic locking members 18 are respectively held in recesses 17 made in forward portions of both side walls of the cover 16. Locking portions 21 of the locking members 18 project forwardly of the cover 16 through slots 19 made in its front wall to communicate with the recesses 17, the projecting end portions of the locking portions 21 being bent inwardly. A fixing projection 22 of each locking member 18 is fixedly inserted in a groove of the cover 16 at the base of the locking portion 21 in each recess 17. The locking member 18 is rearwardly extended out of the cover 16 obliquely thereto and then turned back to form a release lever 23, the inner end of which is resiliently urged against the side wall of the cover 16 in the recess 17.
On the other hand, a conventional receptacle connector 30 has such a structure as depicted in FIG. 3. A body 31 of an insulating material has on its front face a protrusion 32 formed integrally therewith for insertion into the shell 15 of the plug connector 11. The front end face of the protrusion 32 has made therein contact receiving holes 33 in a predetermined pattern of array, in which are embedded receptacle contacts (not shown) for resilient engagement with the plug contact pins 13. The protrusion 32 is fitted into a metallic shell 34, which has its flange 34a secured to the front face of the body 31. Terminals of the receptacle contacts in the body 31 are led out therefrom, though not shown.
On both sides of the protrusion 32 locking pieces 35, which project forwardly of the flange 34a, are fixed by screws 36 to the body 31. Projecting end portions of the locking pieces 35 are bent outwardly from each other.
When the plug connector 11 and the receptacle connector 30 are assembled together, the shell 34 of the latter is fitted into the shell 15 of the former, as shown in FIG. 2. In this instance the locking portions 21 are resiliently displaced outward by the locking pieces 35 and then their bent end portions are locked together, retaining the plug connector 11 and the receptacle connector 30 in their connected state. In this way, the connectors 11 and 30 can easily be connected together simply by urging them against each other, that is, by a single snap-in operation. In order to disconnect them, it is necessary only to urge the release levers 23 toward the recesses 17 as indicated by the arrows 38, by which the locking portions 21 are turned outwardly in opposite directions with the fulcrums at the positions of the fixing projections 22, as indicated by the arrows 39, and are unlocked from the locking pieces 35.
With the conventional plug connector 11 described above, since the shell 15 protrudes forwardly of the front wall of the cover 16, there is the possibility that when the shell 15 is subjected to an external force, for example, when the plug connector 11 happens to be dropped on the floor together with the cover 16, the shell 15 may be deformed and the plug connector 11 cannot be fitted with the receptacle connector 30. Similarly, the locking portions 21 protrude forwardly of the cover 16 and hence are readily deformed or broken by an external force. When the locking portions 21 are deformed, its function of locking the plug connector 11 with the receptacle connector 30 will be lost.
Furthermore, if the release levers 23 of the locking members 18 are pressed too strong when unlocking the connectors 11 and 30, the locking members 18 are deformed or their resiliency is degraded and their normal locking and unlocking functions are lost.
On the other hand, according to the conventional receptacle connector 30, it is necessary to prepare the locking pieces 35 separately of the body 31 and secure the former to the latter by means of screws. This increases the number of parts used and calls for the screw clamping operation. Moreover, there is a possibility that the locking pieces 35 are mounted on the body 31 at a displaced angle .theta. relative to its correct direction, as shown in FIG. 4, making the receptacle connector 30 defective. Even if the locking pieces 35 are not tilted, there are sometimes variations in the spacing between the locking pieces 35 caused during tightening of screws 36, making it impossible to correctly fit the receptacle connector 30 with the plug connector 11.
It is therefore an object of the present invention to provide a plug connector which has a shell and locking portions almost free from the influence of an external force to ensure correct engagement with the mating receptacle connector, and which can be locked into and unlocked from its state of engagement with the receptacle connector through a single manual operation.
Another object of the present invention is to provide a plug connector which can achieve a stable connection and disconnection operation even if the release levers of the locking members are urged too hard for unlocking the connectors from each other.
Another object of the present invention is to provide a plug connector which ensures shielding against electromagnetic waves.
Another object of the present invention is to provide a receptacle connector which is small in the number of parts involved and hence is easy to assemble.
Yet another object of the present invention is to provide a receptacle connector which can correctly be engaged with the plug connector at all times.